Error 526: Invalid SSL certificate

Error 526 happens when Cloudflare is unable to successfully validate the SSL certificate on the origin web server and the SSL setting in the Cloudflare Crypto app is set to Full SSL (Strict) for the website.

The server administrator should review the origin's SSL certificates to ensure they meet the following validation requirements:

The certificate hasn't expired.

The certificate isn't revoked.

The certificate is signed by a certificate authority (such as GlobalSign, Verisign, GeoTrust, Comodo, etc) and is not a self-signed SSL certificate.